NCIt definition : A group of rare disorders that are usually caused by somatic mutations in the PIK3CA
gene, but may rarely be caused by de novo germline mutations. These disorders are
typically characterized by sporadic overgrowth of parts of the body, intellectual
disability, low muscle tone, and vascular malformations with congenital or early childhood
onset. Representative examples include: fibroadipose hyperplasia, CLOVES syndrome,
megalencephaly-capillary malformation syndrome, hemihyperplasia-multiple lipomatosis
syndrome, hemimegalencephaly, and facial infiltrating lipomatosis.;